Bought this 21" HP P1130 flat Trinitron monitor for 20€. Thing is, it doesn't work. Previous owner said it had a very good picture, until it suddenly shut down and never started again. I thought I'd take the gamble for 20€. Not a huge loss, if I can't repair it.

Did some testing and it tries to start, voltages go up and down a few times, and then the PSU shuts down because of overload. Found out damper diode in the horizontal deflection circuit has shorted, and as a concequence it has also broken the transistor in same circuit (also shorted). I'm hopeful that by replacing these it might come back to life.

I think this monitor is similar to Sony CPD-G520, just with HP branded casing.

bearking wrote on 2023-09-09, 09:24:

Today's flea market finds:
20230909_121640.jpg
The Intel DX2-66 had a heatsink glued on...

In boards or just like that?

H3nrik V! wrote on 2023-09-10, 07:30:

bearking wrote on 2023-09-09, 09:24:

Today's flea market finds:
20230909_121640.jpg
The Intel DX2-66 had a heatsink glued on...

In boards or just like that?

No, without the boards. Unfortunatly...
A random guy was selling these 10 and two more P1-s and a Duron 800. He was asking 2 Euros per pcs. At that price I just couldn't leave them. But I'm really happy for the Motorola chip, it is my first 68000, the PR100 and the 386-s.
I wonder the 68040 from what system came from...?

I'd say there was a large chance it came from a Macintosh Quadra, but they got around to all sorts of applications in small numbers.

Odds and ends! 😁

I love the casual shot of an NV1.

😁 OH YEAH! I can check another one of the Unicorns off my list. I am not complaining though. I think that I have a herd of them by now. 😁 Truth be told I lost count. 😁 I must be getting old(er).

Speaking of unicorns getting checked off of lists...

I managed to get an Ati Mach 32. it was pretty high on my list for a good decade...

I paid through the nose, but its going to let me complete a build that has been on the back burner.

What a beauty! 😀

CrFr wrote on 2023-09-09, 10:14:

Bought this 21" HP P1130 flat Trinitron monitor for 20€. Thing is, it doesn't work. Previous owner said it had a very good pict […]
Show full quote

Bought this 21" HP P1130 flat Trinitron monitor for 20€. Thing is, it doesn't work. Previous owner said it had a very good picture, until it suddenly shut down and never started again. I thought I'd take the gamble for 20€. Not a huge loss, if I can't repair it.

Did some testing and it tries to start, voltages go up and down a few times, and then the PSU shuts down because of overload. Found out damper diode in the horizontal deflection circuit has shorted, and as a concequence it has also broken the transistor in same circuit (also shorted). I'm hopeful that by replacing these it might come back to life.

I think this monitor is similar to Sony CPD-G520, just with HP branded casing.

HP_P1130_.jpg

Damper diode rarely fail unless the capacitor in parallel with this diode is faulty could kill diode. As a standard repair, I replace both. And yes, you can parallel deflection capacitors till you get correct value of the original capacitor, as long as voltage of each cap is equal or exceeds it. I did this many times back in the day with no issues. Had to be these capacitors made for deflection use. I had piles of them at work so I cobbled up a kit to meet specific capacitance value.

Cheers,

pentiumspeed wrote on 2023-09-10, 17:07:

Damper diode rarely fail unless the capacitor in parallel with this diode is faulty could kill diode. As a standard repair, I replace both. And yes, you can parallel deflection capacitors till you get correct value of the original capacitor, as long as voltage of each cap is equal or exceeds it. I did this many times back in the day with no issues. Had to be these capacitors made for deflection use. I had piles of them at work so I cobbled up a kit to meet specific capacitance value.

Cheers,

Thank you for you comment, very good information! I suspected that cap might have something to do with the broken diode, so I ordered few of those too, based on just a hunch. Thanks for confirming it.

These parts are impossible to find locally nowadays, so I ordered all of them from Aliexpress. Can't wait to get them, to see if this monitor was worth buying 😀

So the plan is to replace these parts marked with green. Red X means those parts are dead for sure. Capacitor was impossible to test in circuit, because it is in parallel to that shorted diode.

Oh, not from aliexpress. Fakes.

Cheers,

pentiumspeed wrote on 2023-09-10, 23:11:

Oh, not from aliexpress. Fakes.

Cheers,

Fake diodes? Just a pin/lead with some sort of package around it? Ha!

PD2JK wrote on 2023-09-11, 06:42:

Fake diodes? Just a pin/lead with some sort of package around it? Ha!

Yeah, fake diode might be a bit strecth…

When dealing with components, I think the biggest risk of getting scammed is with capacitors sold as high quality brand makes, such as Panasonic or Rubycon. Those may be either fakes (but still somewhat functioning caps), or some terribly old stock. But I’ve ordered countless of other small components such as diodes, transistors, resistors etc from AE without any issues. And I haven’t had any problems with 7400 series logic chips either. And recently I ordered lot of 10 dram chips to upgrade my S3 868 video memory and they were all just fine.

There is certainly a reason to doubt the authenticity of many electronics stuff sold there, but not all is junk.

Capacitors are more likely to be faked, because they are sold in much higher volumes. In niche parts like these CRT transistors and diodes, I would expect the scam to be more likely that parts are marketed as "new" and actually they are extracted from recycled monitors and then cleaned to look nice. Which is fine by me, as long as I get functioning parts.

The sellers I bought the parts from are highly rated, but still I will compare them carefully to the original ones to see if there is something obviously visually wrong. I don't have much choice, because I don't have the expertise to find alternative parts (if those even exist anymore) from reputable western sellers.

This weekend, the main French classifieds site offered 0.99€ shipping for everything.
This occurs 2 or 3 times every years, and this generally brings good stuff because sellers are posting a lot of new ads.
But also, buying is more competitive 😁

So instead of listing what i actually managed to grab, i will list the parts i missed first.

• A nice tested 486 PCI/VLB board + AMD486 + VLB CirrusLogic that was listed for 50€. And that i missed in just the time to load the page. Page loaded : Available. Click on "buy". Error : item sold.
  • Really pissed about this one because i'm actively looking for a modern VLB board for a while. And this one was perfect for my project
• A graphics card lot of about 15 pieces including a Voodoo2, two Voodoo 1 (incl. A Righteous 3D with relays) for ~130€. Sold instantly
• A voodoo Banshee for 17€. Sold instantly
• A QX6850 i needed for my 4CoreDual-Sata2 for ~40€ cancelled because the seller wanted local pickup 1000km from where i live.

That's life 😁

What i could get :

• Turtle Beach Montego II Quadzilla (Vortex2 with WaveBlaster headers and S/PDIF optional bracket) <10€
• Radeon HD 4350 PCI 10€
• (Not hardware) Big Box Quake II 30€

acl wrote on 2023-09-11, 15:00:

This weekend, the main French classifieds site offered 0.99€ shipping for everything.
This occurs 2 or 3 times every years, and this generally brings good stuff because sellers are posting a lot of new ads.

Do they subsidize couriers/post, or do they run own chain of last mile parcel lockers?

PD2JK wrote on 2023-09-11, 06:42:

Fake diodes? Just a pin/lead with some sort of package around it? Ha!

Or just random ones, that do not have say 1500V breakdown voltage, specific recovery profile and other features required to do the task of where they're going to, failing on the spot and in worst case taking other parts with them...
Power transistors, opamps and a number of other things I have bought from chinese sellers in the recent years have been something else than what the markings say on them so caution is absolutely necessary.

rasz_pl wrote on 2023-09-11, 20:52:

acl wrote on 2023-09-11, 15:00:

This weekend, the main French classifieds site offered 0.99€ shipping for everything.
This occurs 2 or 3 times every years, and this generally brings good stuff because sellers are posting a lot of new ads.

Do they subsidize couriers/post, or do they run own chain of last mile parcel lockers?

They work with several delivery services but the 0.99€ offer is generally through MondialRelay. It's generally slower than standard mail, but you can deposit/retrieve your parcel in proximity stores/lockers.

I avoid standard mail if possible. I don't know if it's similar in other countries, but in France, going to the post office is painful. Opening hours are limited and generally not practical for people who work (like Mon-Fri 9:00AM to 5:00PM closed at lunch + Sat morning)
And you have to wait in a line sometimes 20+ minutes

Tiido wrote on 2023-09-12, 00:51:

Or just random ones, that do not have say 1500V breakdown voltage, specific recovery profile and other features required to do the task of where they're going to, failing on the spot and in worst case taking other parts with them...
Power transistors, opamps and a number of other things I have bought from chinese sellers in the recent years have been something else than what the markings say on them so caution is absolutely necessary.

Goes a little bit offtopic, but I’m actually curious, how would you measure this kind of high voltage damper diode to find out if it is indeed genuine and what the stamping says? I’ve never had to do this, so I haven’t never needed to find information how.