[cctalk] Re: HP9825A for sale
In a similar shenanigans vein, I've no explanation for the $20k+ IBM 5120's being listed.I think one of them has been listed as such for over a year now. - Steve v* On Tue, Apr 18, 2023 at 9:09 AM Sellam Abraham via cctalk < cctalk@classiccmp.org> wrote: > On Tue, Apr 18, 2023, 6:59 AM Tom Hunter via cctalk > > wrote: > > > The Ebay listing hasn't sold but has been relisted at the same price. > > > > Indeed, it appears to be: > > https://www.ebay.com/itm/225514573805 > > Non-paying "buyer"? Or shenanigans? > > Sellam > > > >
[cctalk] Re: Schematics for Lear Siegler ADM31?
On Tue, Apr 18, 2023 at 11:04 PM John Robertson via cctalk wrote: > > I like to start with schematics before poking too much... So do I. > > I assume bad caps (will replace with low-ESR high temp), and possibly > blown transistor(s)... > > *And Gregory Beat sent me a link that covers the 1001 SMPS very neatly:* > > http://www.bitsavers.org/pdf/boschert/Boschert_OL25_Single-Stage_Power_Supply_Maintenance_Manual_May79.pdf > > and it was buried on bitsavers - where I went before bothering the list! That is clearly not one of the '2 stage' ones that fail in spectacular ways. It's a relatively conventional SMPSU and shouldn't be too hard to sort out. -tony > > Thanks folks! > > John :-#)# > > > > > > > > >> On Tue, Apr 18, 2023 at 12:20 AM John Robertson via cctalk < > >> cctalk@classiccmp.org> wrote: > >> > >>> I've checked bitsavers.org (Al does a great job!), and a number of > >>> forums, but no luck finding schematics for my ADM31 that I am trying to > >>> resurrect. The power supply has issues and I need to identify a blown > >>> out resistor - the switching supply is a Boschert model 1001 date code > >>> 7943 Revision J. > >>> > >>> John :-#)# > >>> > >>> -- > >>> John's Jukes Ltd. > >>> 7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 > >>> Call (604)872-5757 (Pinballs, Jukes, Video Games) > >>> flippers.com > >>> "Old pinballers never die, they just flip out" > >>> > >>> > > -- >John's Jukes Ltd. > 7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 > Call (604)872-5757 (Pinballs, Jukes, Video Games) >flippers.com >"Old pinballers never die, they just flip out" >
[cctalk] Re: Schematics for Lear Siegler ADM31?
On Wed, Apr 19, 2023 at 2:37 AM Tom Hunter via cctalk wrote: > > ... or four $20 power transistors to protect a 10 cent fuse like on the DEC > VR-14 display. In general the transistor(s) will fail short-circuit, thus taking out the fuse too. Some switch-mode power supplies use special fast-acting fuses which can actually be more expensive than the chopper transistor. -tony
[cctalk] Re: Schematics for Lear Siegler ADM31?
On 4/18/23 18:37, Tom Hunter via cctalk wrote: > ... or four $20 power transistors to protect a 10 cent fuse like on the DEC > VR-14 display. A friend who worked as a DEC CE decades ago, said that "transistor-protected fuses" was a standing joke among that community. --Chuck
[cctalk] Re: Schematics for Lear Siegler ADM31?
... or four $20 power transistors to protect a 10 cent fuse like on the DEC VR-14 display. Tom On Wed, 19 Apr 2023, 6:16 am Fred Cisin via cctalk, wrote: > On 2023/04/18 9:40 a.m., Tony Duell wrote: > > The blown out resistor likely has "blown out" for a reason. > > The replacement will probably suffer the same faith unless you find the > > root cause. > > Isn't there usually a larger, more critical component, such as a > proprietary microprocessor, to blow out to protect the resistor? > >
[cctalk] Re: Schematics for Lear Siegler ADM31?
On Tue, Apr 18, 2023 at 3:16 PM Fred Cisin via cctalk wrote: > On 2023/04/18 9:40 a.m., Tony Duell wrote: > > The blown out resistor likely has "blown out" for a reason. > > The replacement will probably suffer the same faith unless you find the > > root cause. > > Isn't there usually a larger, more critical component, such as a > proprietary microprocessor, to blow out to protect the resistor? > That's only true with Commodore 64's. Sellam
[cctalk] Re: Schematics for Lear Siegler ADM31?
On 2023/04/18 9:40 a.m., Tony Duell wrote: The blown out resistor likely has "blown out" for a reason. The replacement will probably suffer the same faith unless you find the root cause. Isn't there usually a larger, more critical component, such as a proprietary microprocessor, to blow out to protect the resistor?
[cctalk] Re: Schematics for Lear Siegler ADM31?
On 2023/04/18 9:40 a.m., Tony Duell wrote: On Tue, Apr 18, 2023 at 2:51 PM Tom Hunter via cctalk wrote: The blown out resistor likely has "blown out" for a reason. The replacement will probably suffer the same faith unless you find the root cause. As soon as I saw 'Boschert' mental alarm bells triggered Boschert made a particularly unfriendly (to the repairer) type of SMPSU which I call the '2 stage'. I can explain how it works if necessary, but be warned that with one of those if a particular power transistor fails (and it often does), it takes out a couple of other power transistors, the current sense resistor, numerous small transistors, the regulator chip, the fuse and sometime PCB tracks. They're not all like that, but I will agree that a burnt-out resistor in an SMPSU nearly always means other components have failed. It's likely the same PSU was used in other devices, you might want to look through all the service manuals you can find to see if it turns up. Can you make a photo of the PSU available somewhere in case somebody recognises it. -tony I like to start with schematics before poking too much... Photo of the SMPSU: https://www.flippers.com/images/ADM31_Terminal/Boschert_1001_ADM31_PowerSupply.jpg Burnt Resistor: https://www.flippers.com/images/ADM31_Terminal/Boschert_1001_ADM31_PowerSupply-burnt_resistor.jpg Schematics preferred, under the power supply is one I found on bitsavers for a slightly later model terminal. If needed I will draw them up myself, I just don't want to spend a couple of hours sketching it out if I can find a proper drawing. I assume bad caps (will replace with low-ESR high temp), and possibly blown transistor(s)... *And Gregory Beat sent me a link that covers the 1001 SMPS very neatly:* http://www.bitsavers.org/pdf/boschert/Boschert_OL25_Single-Stage_Power_Supply_Maintenance_Manual_May79.pdf and it was buried on bitsavers - where I went before bothering the list! Thanks folks! John :-#)# On Tue, Apr 18, 2023 at 12:20 AM John Robertson via cctalk < cctalk@classiccmp.org> wrote: I've checked bitsavers.org (Al does a great job!), and a number of forums, but no luck finding schematics for my ADM31 that I am trying to resurrect. The power supply has issues and I need to identify a blown out resistor - the switching supply is a Boschert model 1001 date code 7943 Revision J. John :-#)# -- John's Jukes Ltd. 7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 Call (604)872-5757 (Pinballs, Jukes, Video Games) flippers.com "Old pinballers never die, they just flip out" -- John's Jukes Ltd. 7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 Call (604)872-5757 (Pinballs, Jukes, Video Games) flippers.com "Old pinballers never die, they just flip out"
[cctalk] Re: Delivery woes
Mail lists are harder to manage, and why forums and social media have supplanted them. I have brought this same subject up before, but not everyone seems to be interested in or has access to manage their DNS this way in a practical manner. I throw this back at the CPANELs and such of the world to make things like SPF and DKIM part of the account set up. On Tue, Apr 18, 2023 at 2:27 PM Dennis Boone via cctalk < cctalk@classiccmp.org> wrote: > Folks, > > As I try to track down why various subscribers are getting booted from > the list in the last couple of days, I'm noticing that a number of you > are subscribed from an address that forwards elsewhere. > > This works poorly. > > TL;DR follows, but basically this is brought to you by the fact that > modern email sucks almost as much because of the anti-spam processes as > because of the spam itself. In the modern world, forwarding is pretty > much dead on arrival. Avoid it where possible. I'll be over here > swearing right along with you. > > TL;DR: to be able to deliver any email at all these days, we have to > comply with a couple of schemes designed to make it harder to forge mail > -- DKIM and SPF. The combined effect of making the necessary > declarations in the DNS entries for classiccmp.org is that if you try to > forward mail, you look like you're _impersonating_ classiccmp.org. Many > large providers (google, yahoo, etc.) refuse such mail. > > The same anti-spam mechanisms also make it difficult to run a proper RFC > compliant mailing list, because then classiccmp.org would be sending > mail with _your_ From: address, making classiccmp.org look like an > impersonator. Still $w34ring. > > Cheers, > > De >
[cctalk] Delivery woes
Folks, As I try to track down why various subscribers are getting booted from the list in the last couple of days, I'm noticing that a number of you are subscribed from an address that forwards elsewhere. This works poorly. TL;DR follows, but basically this is brought to you by the fact that modern email sucks almost as much because of the anti-spam processes as because of the spam itself. In the modern world, forwarding is pretty much dead on arrival. Avoid it where possible. I'll be over here swearing right along with you. TL;DR: to be able to deliver any email at all these days, we have to comply with a couple of schemes designed to make it harder to forge mail -- DKIM and SPF. The combined effect of making the necessary declarations in the DNS entries for classiccmp.org is that if you try to forward mail, you look like you're _impersonating_ classiccmp.org. Many large providers (google, yahoo, etc.) refuse such mail. The same anti-spam mechanisms also make it difficult to run a proper RFC compliant mailing list, because then classiccmp.org would be sending mail with _your_ From: address, making classiccmp.org look like an impersonator. Still $w34ring. Cheers, De
[cctalk] Re: VCF East 2023 photos
It shouldn't be "part of the experience". It's poor planning and poor management of the consignment area on the part of the organizers. This same thing happened at VCF "West" last year and it was a catastrophe. There was a line snaking down the hallway at least a fifty people deep and they were waiting for 2-3 HOURS before it actually started moving. That was 2-3 hours that attendees weren't in the exhibit/speaker hall engaging with the exhibitors and their exhibits, and listening to the speakers. I'm really disappointed to hear that, despite their prior experience, it seems like they have not done anything to address this completely unacceptable and entirely avoidable scenario. Every bit of space that is currently available at InfoAge was used for the event. Attendence jumped over prior years and the demand was unpredictable. The weather in that area can be cold and rainy so outdoors use is limited in planning. I figured there would be blowout attendence at the 3pm streamer panel in Saturday, but crowd wasn't an issue. Meanwhile at the dedicated swap meets at InfoAge attendence wasn't that crazy at the last one. Maybe it's because it's tax return time? If VCF could raise enough money to finish off their new space at InfoAge and get a CO that would help a ton next year. But that is quite a bit of money intertwined with government legal red tape. Trust me there will be big discussions about how to try to fix it for the future. Also the event could use more volunteers for next year as well. - Ethan
[cctalk] Re: Schematics for Lear Siegler ADM31?
On 4/18/23 09:40, Tony Duell via cctalk wrote: > On Tue, Apr 18, 2023 at 2:51 PM Tom Hunter via cctalk > wrote: >> >> The blown out resistor likely has "blown out" for a reason. >> The replacement will probably suffer the same faith unless you find the >> root cause. > > > As soon as I saw 'Boschert' mental alarm bells triggered > > Boschert made a particularly unfriendly (to the repairer) type of > SMPSU which I call the '2 stage'. I can explain how it works if > necessary, but be warned that with one of those if a particular power > transistor fails (and it often does), it takes out a couple of other > power transistors, the current sense resistor, numerous small > transistors, the regulator chip, the fuse and sometime PCB tracks. True, but Bob Boschert was a pioneer in the field working with what components were available. So don't be too hard on him. --Chuck
[cctalk] Re: Schematics for Lear Siegler ADM31?
On Tue, Apr 18, 2023 at 2:51 PM Tom Hunter via cctalk wrote: > > The blown out resistor likely has "blown out" for a reason. > The replacement will probably suffer the same faith unless you find the > root cause. As soon as I saw 'Boschert' mental alarm bells triggered Boschert made a particularly unfriendly (to the repairer) type of SMPSU which I call the '2 stage'. I can explain how it works if necessary, but be warned that with one of those if a particular power transistor fails (and it often does), it takes out a couple of other power transistors, the current sense resistor, numerous small transistors, the regulator chip, the fuse and sometime PCB tracks. They're not all like that, but I will agree that a burnt-out resistor in an SMPSU nearly always means other components have failed. It's likely the same PSU was used in other devices, you might want to look through all the service manuals you can find to see if it turns up. Can you make a photo of the PSU available somewhere in case somebody recognises it. -tony > > On Tue, Apr 18, 2023 at 12:20 AM John Robertson via cctalk < > cctalk@classiccmp.org> wrote: > > > I've checked bitsavers.org (Al does a great job!), and a number of > > forums, but no luck finding schematics for my ADM31 that I am trying to > > resurrect. The power supply has issues and I need to identify a blown > > out resistor - the switching supply is a Boschert model 1001 date code > > 7943 Revision J. > > > > John :-#)# > > > > -- > > John's Jukes Ltd. > > 7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 > > Call (604)872-5757 (Pinballs, Jukes, Video Games) > > flippers.com > > "Old pinballers never die, they just flip out" > > > >
[cctalk] Re: Schematics for Lear Siegler ADM31?
I’ve found that following traces and identifying components that connect to either side of the failed resistor is usually a good start for finding root cause. Shorted power transistors, diodes, or portions of bridge rectifiers have been the root cause of cascading failures in my cases. -Royce > On Apr 18, 2023, at 06:51, Tom Hunter via cctalk > wrote: > > The blown out resistor likely has "blown out" for a reason. > The replacement will probably suffer the same faith unless you find the > root cause. > >> On Tue, Apr 18, 2023 at 12:20 AM John Robertson via cctalk < >> cctalk@classiccmp.org> wrote: >> >> I've checked bitsavers.org (Al does a great job!), and a number of >> forums, but no luck finding schematics for my ADM31 that I am trying to >> resurrect. The power supply has issues and I need to identify a blown >> out resistor - the switching supply is a Boschert model 1001 date code >> 7943 Revision J. >> >> John :-#)# >> >> -- >> John's Jukes Ltd. >> 7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 >> Call (604)872-5757 (Pinballs, Jukes, Video Games) >> flippers.com >> "Old pinballers never die, they just flip out" >> >>
[cctalk] Re: HP9825A for sale
On Tue, Apr 18, 2023, 6:59 AM Tom Hunter via cctalk wrote: > The Ebay listing hasn't sold but has been relisted at the same price. > Indeed, it appears to be: https://www.ebay.com/itm/225514573805 Non-paying "buyer"? Or shenanigans? Sellam >
[cctalk] Re: HP9825A for sale
The Ebay listing hasn't sold but has been relisted at the same price. On Tue, Apr 18, 2023 at 12:16 AM John Robertson via cctalk < cctalk@classiccmp.org> wrote: > On 2023/04/17 9:12 a.m., Sellam Abraham via cctalk wrote: > > My initial reaction is that $2,000 seems a "bit" optimistic. > > > > That being said, I'm surprised to see (on eBay's Terapeak) a couple of > > these sold within the past year for around $1,100. > > > > Sellam > > One sold on eBay for $2492USD...Apr 6, 2023: > > https://www.ebay.com/itm/225512121074?hash=item348191e2f2 > > John :-#)# > > > > > On Mon, Apr 17, 2023, 8:52 AM Steve Lewis via cctalk < > cctalk@classiccmp.org> > > wrote: > > > >> There is a gentlemen in New Jersey willing to sell his HP9825A > >> > >> I believe he is the original owner. It has 4 ROM cartridges (that go in > >> the front) and several data cartridges for the slot on the top left. > >> > >> He is asking $2000 but can probably negotiate (as he didn't find any > takers > >> in VCF East). As far as he knows, everything still works (LED lights > came > >> on when he powered it up a few months ago). > >> > >> I've met this seller and can vouch for him, but I don't know much about > >> this particular item. > >> > >> I have some photos of it at the bottom of this page: > >> https://voidstar.blog/vcf-east-2023-part-3/ > >> > >> I may try a VCF forum topic about it. Just trying to help him find a > good > >> home for the equipment. E-mail/reply direct and I can provide some > contact > >> info. > >> > >> (BTW not sure if my cctalk posts are working anymore??) > >> > >> -Steve / voidstar > >> > > -- > John's Jukes Ltd. > 7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 > Call (604)872-5757 (Pinballs, Jukes, Video Games) > flippers.com > "Old pinballers never die, they just flip out" > >
[cctalk] Re: Schematics for Lear Siegler ADM31?
The blown out resistor likely has "blown out" for a reason. The replacement will probably suffer the same faith unless you find the root cause. On Tue, Apr 18, 2023 at 12:20 AM John Robertson via cctalk < cctalk@classiccmp.org> wrote: > I've checked bitsavers.org (Al does a great job!), and a number of > forums, but no luck finding schematics for my ADM31 that I am trying to > resurrect. The power supply has issues and I need to identify a blown > out resistor - the switching supply is a Boschert model 1001 date code > 7943 Revision J. > > John :-#)# > > -- > John's Jukes Ltd. > 7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 > Call (604)872-5757 (Pinballs, Jukes, Video Games) > flippers.com > "Old pinballers never die, they just flip out" > >
[cctalk] AT Customer Service
Fred Cisin wrote: On Mon, 17 Apr 2023, AT Customer Service via cctalk wrote: Sorry, I forgot to post the location. I'm in Kent, Washington. USA. disregard the AT customer service. Have E-mails in to them. not sure what going on there, but its at anything is possible. With a user name of "AT Customer Service", we speculated that it might be the Philipines, or India. :-) Is there a country called Oxymoronia?
