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View Full Version : ST-V booting problem. FIXED. Damn SH-2



NeoTurfMasta
11-26-2014, 12:53 PM
Games won't boot. System has been sitting unplayed for a month or so. On a shelf, untouched. I go to put it back on the same supergun, black screen.

OK, so I put the original ENG bios in and an original Die Hard cart. Memory tests pass on system and cart. Black screen after Patent screen.

Ideas?

Fixed:

Resoldered all the pins on the SH-2 CPUs. Boots right up now. No freezing or constant black screen.

skate323k137
11-26-2014, 02:27 PM
I'm sure it goes without saying but you checked your voltages right? My ST-V acts really weird if it's under 5.1 at the JAMMA edge (I leave it right about 5.1 like my NAOMI).

NeoTurfMasta
11-26-2014, 02:47 PM
I'm sure it goes without saying but you checked your voltages right? My ST-V acts really weird if it's under 5.1 at the JAMMA edge (I leave it right about 5.1 like my NAOMI).

Hmmmm, mine holds steady at 5v exactly. I'll mess with the voltage a bit and see if I get better results. I wasn't aware it was so picky.

skate323k137
11-26-2014, 03:11 PM
When mine was 5.0 at the edge I'd get freezing, sound glitching, just weird stuff. I hope it's an easy adjustment in your case like it was in mine.

NeoTurfMasta
12-09-2014, 01:43 PM
Still no luck with a new PSU and voltage. The only game I can seem to boot is Golden Axe. Everything else is backscreen.

EDIT:

I have been able to boot more games, but they will either work once, then freeze a few seconds into the game. I'm beyond annoyed with ST-V. Time to get rid of the multicart, I'm not wasting another minute on this hardware.

EDIT 2: It was the second SH-2 cpu.

urmyokazu
12-09-2014, 08:56 PM
Thanks so much for posting this, I had the exact same problem. I tried reflowing the solder on the SH-2 chip and that didn't do anything at first. Then I realized there was a 2nd SH-2 on the board, and that one had a lot of left over flux residue and in general looked sloppier. Reflowed the solder on that SH-2 and everything is working now.

Thanks again NTM!

kuze
12-10-2014, 05:51 PM
Fixed:

Resoldered all the pins on the SH-2 CPUs. Boots right up now. No freezing or constant black screen.

Hey NTM, thank you so much for posting the fix! I had the same problems with mine and was able to resolve it by reflowing half of the pins on my secondary sh2.

For those with the same issue, the slave sh2 is on the back side of the board closest to the cart slot.

When I ran the dual CPU test I didn't get a 'bad' returned, it just hung on 'slave sh2 works' with no good/bad indicator displayed. After adding some flux and touching the pins, the test comes back as good. Rock on!

chrd
12-10-2014, 05:59 PM
I'm beyond annoyed with ST-V.

I can certainly relate to that. Although it's a cartridge based system it does not seem to want cartridges being changed (flexing of the board perhaps?). I've had two ST-V motherboards die on me while they were being handled with the utmost respect...

channelmaniac
12-10-2014, 09:21 PM
They flex too much. Popped CPU pins are common and the first thing I do when troubleshooting a dead one is to reflow both of the SH-2 CPUs.

Memory problems? More likely a CPU soldering problem. Cartridge errors? Reflow the CPUs. Won't boot? Reflow the CPUs.

:)

kuze
12-11-2014, 10:33 AM
They flex too much. Popped CPU pins are common and the first thing I do when troubleshooting a dead one is to reflow both of the SH-2 CPUs.

Memory problems? More likely a CPU soldering problem. Cartridge errors? Reflow the CPUs. Won't boot? Reflow the CPUs.

:)

Any idea whether either of the sh2 processors might be responsible for p1 left/right sticking on? Or would that be more likely the result of a bad resistor network close to the jamma edge?

channelmaniac
12-15-2014, 12:39 PM
Bad resistor network or chip input. Easy to track down with a logic probe.