Andy King 📺
@crtdatabase.com
Software Engineer, creator of CRTDatabase.com.
Discord Handle: andy.king
Discord Server: https://discord.com/invite/qMtWasTN
Twitter: https://twitter.com/dorksince93
Website: https://crtdatabase.com
Support Me: https://patreon.com/andyking
Discord Handle: andy.king
Discord Server: https://discord.com/invite/qMtWasTN
Twitter: https://twitter.com/dorksince93
Website: https://crtdatabase.com
Support Me: https://patreon.com/andyking
I've been working on lots of cassette decks lately. The mechanical aspects of them make it quite fun and the metrics of performance are well understood. It's cool seeing the direct results of proper maintenance reflected in the speed consistency, wow and flutter rating, and frequency response.
April 14, 2025 at 4:31 AM
I've been working on lots of cassette decks lately. The mechanical aspects of them make it quite fun and the metrics of performance are well understood. It's cool seeing the direct results of proper maintenance reflected in the speed consistency, wow and flutter rating, and frequency response.
Removed the RIFA caps on this Apple Lisa and recapped the power and video boards while I was in there. What a wonderfully modular computer design for its time...
April 4, 2025 at 1:09 AM
Removed the RIFA caps on this Apple Lisa and recapped the power and video boards while I was in there. What a wonderfully modular computer design for its time...
Update: its fixed! Turns out there is a 5v reg on the TV board for the SNES to use, but that wasnt even the problem. There is a PNP transistor that pulls the 5v low for the reset button and that transistor was dead. So 5v was being pulled low 100% of the time. I'll document more about it on my site
March 15, 2025 at 6:12 AM
Update: its fixed! Turns out there is a 5v reg on the TV board for the SNES to use, but that wasnt even the problem. There is a PNP transistor that pulls the 5v low for the reset button and that transistor was dead. So 5v was being pulled low 100% of the time. I'll document more about it on my site
I've gone and labeled all the chips I can read right now. Nothing resembling a regulator so that leaves me to assume the 12v to 5v regulation is done discreetly somewhere in this 2nd pic
March 11, 2025 at 9:30 PM
I've gone and labeled all the chips I can read right now. Nothing resembling a regulator so that leaves me to assume the 12v to 5v regulation is done discreetly somewhere in this 2nd pic
Switching the SNES power switch on/off changes where the 12v supply is - which seems to be a logic controlled operation not a simple "switch changed the pins that 12v feed" situation. Power switch doesn't ever have 12v. So maybe something is alive, I don't know. Help! Lol
March 11, 2025 at 6:09 PM
Switching the SNES power switch on/off changes where the 12v supply is - which seems to be a logic controlled operation not a simple "switch changed the pins that 12v feed" situation. Power switch doesn't ever have 12v. So maybe something is alive, I don't know. Help! Lol
The SNES is from a Sharp SF1 where the 12v power supply for the SNES blew up. I've repaired the PSU and restored 12v power to the SNES but it does not seem to be running. Only thermal activity I see is a couple warm transistors. The Nintendo chips are not warm at all.
March 11, 2025 at 6:09 PM
The SNES is from a Sharp SF1 where the 12v power supply for the SNES blew up. I've repaired the PSU and restored 12v power to the SNES but it does not seem to be running. Only thermal activity I see is a couple warm transistors. The Nintendo chips are not warm at all.
I'm putting out an SOS for anyone in the community that knows SNES hardware like the back of their hand. I don't mean like installing mods or replacing capacitors, I need someone who could diagnose a bad CPU, bad smd transistor, etc. this is for a rare Sharp SF1 tv 🧵
March 11, 2025 at 6:09 PM
I'm putting out an SOS for anyone in the community that knows SNES hardware like the back of their hand. I don't mean like installing mods or replacing capacitors, I need someone who could diagnose a bad CPU, bad smd transistor, etc. this is for a rare Sharp SF1 tv 🧵
One more tip. You need to be careful when recapping these 90s Sony PVM boards. The plated through holes are crap quality and they will come out along with the capacitor legs if you overheat them while pulling. If you rip one out you need to cross referencen the (continued...)
February 25, 2025 at 5:51 AM
One more tip. You need to be careful when recapping these 90s Sony PVM boards. The plated through holes are crap quality and they will come out along with the capacitor legs if you overheat them while pulling. If you rip one out you need to cross referencen the (continued...)
Another question I get is what causes the capacitors to go bad in some 14MXX PVMs but not others, since they are all the same general age? The answer is heat and operating hours. Capacitors specifically degrade over time from excessive heat. One thing responsible for excessive heat is dirt buildup.
February 25, 2025 at 5:51 AM
Another question I get is what causes the capacitors to go bad in some 14MXX PVMs but not others, since they are all the same general age? The answer is heat and operating hours. Capacitors specifically degrade over time from excessive heat. One thing responsible for excessive heat is dirt buildup.
When C572 gets worn out, its ESR worsens and it becomes leaky. Leaky capacitors will perform the worst when they are cold (on power-up). Once they reach operating temperature they will perform better, which is why the visual problem improves over time. 32ohm ESR vs 3ohm ESR on the old cap vs new.
February 25, 2025 at 5:51 AM
When C572 gets worn out, its ESR worsens and it becomes leaky. Leaky capacitors will perform the worst when they are cold (on power-up). Once they reach operating temperature they will perform better, which is why the visual problem improves over time. 32ohm ESR vs 3ohm ESR on the old cap vs new.
Fixed a somewhat common issue on this Sony PVM 14M4J. The corners of the image were folded in on power-up and would slowly unfold into somewhat normal appearance after a few minutes. C572's responsible for this problem, its a filter capacitor on the pin amp section of the horizontal output circuit 🧵
February 25, 2025 at 5:51 AM
Fixed a somewhat common issue on this Sony PVM 14M4J. The corners of the image were folded in on power-up and would slowly unfold into somewhat normal appearance after a few minutes. C572's responsible for this problem, its a filter capacitor on the pin amp section of the horizontal output circuit 🧵
Successfully RGB modded this RF-only TV using a board from AliExpress. Hopefully the China import nonsense gets sorted soon so I can order more of them...
February 8, 2025 at 3:56 AM
Successfully RGB modded this RF-only TV using a board from AliExpress. Hopefully the China import nonsense gets sorted soon so I can order more of them...
Now all that remained is replacing a lot of these old leaking capacitors and doing a full calibration.
January 15, 2025 at 7:18 AM
Now all that remained is replacing a lot of these old leaking capacitors and doing a full calibration.
After checking all the reference waveforms and voltages that should lead to getting horizontal drive from this IC, it seemed pretty clear that the problem had to be the IC itself. Nothing else was amiss. Sure enough, everything started working after replacing that IC.
January 15, 2025 at 7:18 AM
After checking all the reference waveforms and voltages that should lead to getting horizontal drive from this IC, it seemed pretty clear that the problem had to be the IC itself. Nothing else was amiss. Sure enough, everything started working after replacing that IC.
So why is there no horizontal drive input? Surely it couldn't be a bad horizontal jungle IC, right? I sub'd in horizontal drive using my Sencore HA2500 and sure enough the whole horizontal circuit came to life. All this TV is missing is a horizontal drive signal, it wants to live
January 15, 2025 at 7:18 AM
So why is there no horizontal drive input? Surely it couldn't be a bad horizontal jungle IC, right? I sub'd in horizontal drive using my Sencore HA2500 and sure enough the whole horizontal circuit came to life. All this TV is missing is a horizontal drive signal, it wants to live
Without horizontal oscillation the horizontal drive transistor is just latched on constantly, which sends B+ to ground via that load resistor. The poor 1W resistor can only handle that for about 5 seconds before it starts smoking.... This is going to be so fun during testing....
January 15, 2025 at 7:18 AM
Without horizontal oscillation the horizontal drive transistor is just latched on constantly, which sends B+ to ground via that load resistor. The poor 1W resistor can only handle that for about 5 seconds before it starts smoking.... This is going to be so fun during testing....
The customer picked this up in working condition but unfortunately it only lasted about 15 minutes before it quit. You might think it'd just be a simple recap job but nope! This was a fully fledged diagnostic case.
January 15, 2025 at 7:18 AM
The customer picked this up in working condition but unfortunately it only lasted about 15 minutes before it quit. You might think it'd just be a simple recap job but nope! This was a fully fledged diagnostic case.
Sony KV-1224R fully repaired and restored 🧵
January 15, 2025 at 7:18 AM
Sony KV-1224R fully repaired and restored 🧵
Forgot I had this other screenshot I could attach that would also demonstrate it's the japanese release lol.
January 14, 2025 at 3:35 AM
Forgot I had this other screenshot I could attach that would also demonstrate it's the japanese release lol.
Replaced all the leaking capacitors on this Apple ColorMonitor //e. It was losing its image after running for a while, now it's good to go. I love how composite looks on this, got a lot of 80s charm.
January 14, 2025 at 12:10 AM
Replaced all the leaking capacitors on this Apple ColorMonitor //e. It was losing its image after running for a while, now it's good to go. I love how composite looks on this, got a lot of 80s charm.
Well actually I'm dumb and polarity matters since this power brick isn't grounded. Center negative is just more annoying to clip up to so I avoided it... With correct polarity it has no serious ripple but the unloaded output is 7vdc. Too high for the sensitive D6C.
January 11, 2025 at 1:33 AM
Well actually I'm dumb and polarity matters since this power brick isn't grounded. Center negative is just more annoying to clip up to so I avoided it... With correct polarity it has no serious ripple but the unloaded output is 7vdc. Too high for the sensitive D6C.
I bought a bad Walkman D6C for parts recently. The speed control is not working.. typical cause for that is fried power IC inside from connecting the wrong (or a failing) 6vdc center-negative power brick. I asked them to bundle in the PSU they used to test it, and yep this PSU is guilty of murder...
January 11, 2025 at 12:30 AM
I bought a bad Walkman D6C for parts recently. The speed control is not working.. typical cause for that is fried power IC inside from connecting the wrong (or a failing) 6vdc center-negative power brick. I asked them to bundle in the PSU they used to test it, and yep this PSU is guilty of murder...
This old Vectrex had a shrinking width due to failing capacitors. Replaced them all and it's good as new! I usually don't bother with full recaps but in cases like this where all the stock ones are garbage it's pretty much a requirement.
December 20, 2024 at 3:08 AM
This old Vectrex had a shrinking width due to failing capacitors. Replaced them all and it's good as new! I usually don't bother with full recaps but in cases like this where all the stock ones are garbage it's pretty much a requirement.
I was looking through a toy catalog for Christmas gift ideas and noticed something odd. This "Arcades in a Tin" toy is a direct ripoff of Helder's MintyPi... I'm not aware of what licensing the project had (if any) but I was very surprised to see this regardless. sudomod.com/mintypi-v3-5/
December 9, 2024 at 7:23 PM
I was looking through a toy catalog for Christmas gift ideas and noticed something odd. This "Arcades in a Tin" toy is a direct ripoff of Helder's MintyPi... I'm not aware of what licensing the project had (if any) but I was very surprised to see this regardless. sudomod.com/mintypi-v3-5/
People keep asking me WTF I'm going to do with such a tiny SVGA CRT and my answer is who cares, have you seen how smol it is!? 😂 Check out its size relative to a Dreamcast.
November 21, 2024 at 1:23 AM
People keep asking me WTF I'm going to do with such a tiny SVGA CRT and my answer is who cares, have you seen how smol it is!? 😂 Check out its size relative to a Dreamcast.