Recent content by matthew180

The original TMS4116 DRAM come in 150ns, 200ns, and 250ns speeds. I'm pretty sure the Williams boards need the 150ns versions since they are doing a lot of access multiplexing on the VRAM. The MN41C4256 (Motorola) 4x256K DRAM seems to come in 70ns and 80ns speeds, so any variant is easily be...

Depending on the failure, piggybacking an IC that is part of a data bus does not work. I realize it is the easy/hopeful way to test, but without knowing the failure mode of the part you cannot be sure (unless you get lucky and it *just works*). I have personally never seen it work for digital...

I have a Centipede that started having trackball issues all of a sudden. The motion seems very slow, like the ball is not spinning the encoder wheels. The parts are not terribly old, but I still went ahead and replaced the bearings and made sure everything inside was clean, etc. Visually...

TL;DR: Free. Two G07 monitors, recently non-working. I am in SoCal, greater Los Angles area and prefer not to ship. I'm happy to drive and meet to help with a pickup. However, I will ship if you *really* want them and are willing to pay for the shipping. Please PM if interested. Longer...

@Ed, I was not powering up long enough to see if the screen would warm up since I did not want to blow out another FB. However, I just turned it on and let it warm up for a minute with the lights off. No neck glow, no visible raster. HOT has 160V on it. This is the status of each: T502...

Ah, I see. Sure, I'll do a full PCB trace continuity check, it should not take too long. I'm looking on your website for an X501 replacement too, do you have any? If so, what is the part number?

I have a spare IC501 in the extra PCB I just picked up, but I don't know for sure if that it would be good. Are there any bench tests (or in-circuit measurements) to know if IC501 has failed? I'll order a few (assuming they are available), and pull it and put in a socket. Is there a list of...

Pulled X701, no change, B+ is still +148V and won't adjust. X701 seemed to test fine on the bench, compared to another X701. I got a spare GO7 PCB, so I pulled and tested T501. 55 ohms across one coil, about 0.5 ohms on the other. Both T501s that I have tested the same. Pulled X501 and...

Does anyone know where I can get Street Fighter schematics?

Thanks Tron Guy, I'll pull X701 tonight and see what happens (what does X701 do anyway?) After I posted last night I did some additional searching and found a lot of threads (mostly posted by you ;-) ) related to a high B+. I should have found the GO7 flowchart earlier... I feel like an idiot...

I have now replaced the VR, HOT, and FB. F901 does not blow now, but B+ is still pegged at 170V and will not adjust. This seems to be back where I was after my original re-cap, VR, HOT, and FB replacement, i.e. the monitor worked for a while but then failed completely. I removed all the...

Thanks for the links and vendor suggestions, I'll check them out. I have seen flybacks for sale with and without the focus and screen adjustments. Does it matter?

Bah, that would suck if it was the FB, I *just* replaced it (and the HOT) when I did the caps. I'll test the HOT. How does the HOT short to the frame? Is that due to incorrect install, or maybe the insulator failing? Is there a guide somewhere that shows how a good HOT will read with the ohm...

It worked for a few hours over a couple of sessions before failing. So you don't think I can adjust B+ with the other part of the monitor disconnected? What is the resistance supposed to be from the B+ test point to ground? I'm getting about 2 to 3 ohms, which seems really low to me.

I recapped a G07, replaced the flyback, and the HOT. It worked fine for a while, then went out. I realized I did not do the B+ adjustment after recapping, but now it keeps blowing the smaller 1.25A fuse F901. I lifted two wires (W416 and W420) that provide B+ to the rest of the monitor...