I have an account on the other platform but haven't started regular posting there... haven't seen enough activity yet. But if you want to preemptively follow, here's the details:

CRTDatabase should be back up within ~30 min

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's a PNP transistor that pulls the 5v low for reset and that transistor was dead. So 5v was being pulled low 100% of the time. I'll document the fix on crtdb.

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's a PNP transistor that pulls the 5v low for reset and that transistor was dead. So 5v was being pulled low 100% of the time. I'll document the fix on crtdb.

Forgot to share a full pic of the back

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.

The snes I am working on is not a recognizable variation of the SNES hardware, does not follow the published schematics, and runs off 12v instead of 10v. I am hoping someone could look at the board and recognize what each area is (continued)

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 knows a SNES like the back of their hand and could diagnose a bad CPU, bad smd transistor, etc 🧵

https://t.co/r9CO6k61bJ

Documented on CRT Database as of today.

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.

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....

Checking nearby voltages against the schematic reference I noticed missing B+ voltage at the horizontal drive transistor's collector. Probing around revealed an open load resistor, which I replaced. Immediately after testing the TV again I realized why that resistor was blown...

After checking the obvious with B+ and power reg it seemed like the power section should be working just fine. Checking for horizontal drive at the HOT revealed the problem - no horizontal oscillation. First thing to check is if the horizontal jungle has VCC - which it did.

First I wanted to make sure the condition of the TV was worth putting time into. The tube tested strong enough that it should produce a nice picture, and I don't see anything burned to toast inside, so it seems like a safe enough bet...

The TV wouldn't turn on at all. All it'd do was click a relay every time I pressed Power. Since this TV is capable of being remotely controlled, it has a standby circuit that keeps it awake to respond to remote power-on. This circuit was working, but beyond that the TV was dead.

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 CRT fully repaired and restored 🧵