11 replies to this topic

[junkyardjedis]

Hello all,
I am new to the jaguar scene and stumbled upon one at a yard sale. I picked up the jaguar with quite a few games noteably Tempest 2000 and AVP. It also came with the Jaguar CD along with one game. I have both original power supplies however, when I power up the system all I get is a black screen via Rf cable. I tested the RF cable with my 3DO and it works properly. I cleaned the cartridge insert with alcohol at this point I am thinking that there is an issue with the boot rom itself. Rather than buy a replacement system I would like to replace the boot rom itself if that would correct the issue. Either way I am willing to try anything to repair the system. Any help would be great!
Regards
Jim

[Zerosquare]

Unless you have a reason to think the boot ROM specifically is defective, it is unlikely to be bad.

I suppose the power LED lights up, right ?

I'd start by checking if you have video and/or sound by connecting to the A/V outputs directly. That way, you can rule out a defective RF modulator.

Check these pictures if you need help :
A/V connector pinout
A/V signals on the motherboard

[junkyardjedis]

Sounds Good I will try to test the sound to see if I get any results. When I did the have box open I felt that "Tom and Jerry" were getting warm.
Regards and Thank You
Jim

[junkyardjedis]

I stripped down a pair of RCA audio jacks and touched both wires to the ones on the diagram on top and bottom and didnt get any results.. How do I go about testing the video there seems like so many wires. At this point I just would like to see if there is any picture. It doesnt matter if its clear or not if this resolves the problem I will simply buy a rca plug then because I know it will resolve the issue.

[junkyardjedis]

Ok I did some more poking around... and here is where I am at now. The red led does light up when I put a cartridge in, but I stripped down one side of a set of av cables. I contacted the yellow/ video cable ends to 10b and 11b with no results. As well as doing the same with the audio cables on 1b 2b 1a and 2a. With no results either any futher suggestions?
Regards
Jim

Edited by junkyardjedis, Sun May 22, 2011 1:26 PM.

[busterm]

junkyardjedis, on Sun May 22, 2011 10:22 AM, said:

I stripped down a pair of RCA audio jacks and touched both wires to the ones on the diagram on top and bottom and didnt get any results.. How do I go about testing the video there seems like so many wires. At this point I just would like to see if there is any picture. It doesnt matter if its clear or not if this resolves the problem I will simply buy a rca plug then because I know it will resolve the issue.

Try doing the video ground with 4A instead of the one you used. I've come across a few times when moding Jaguars for Svideo or Compsoit that 4A is the most reliable ground for the composite video

[junkyardjedis]

no go.. I tried both grounds with no luck.. I did test the rca by sticking the wires into the back of the plugs on my 3do to test the cable itself and it worked fine.. Is there any other options?

Edited by junkyardjedis, Mon May 23, 2011 10:33 AM.

[busterm]

junkyardjedis, on Mon May 23, 2011 10:32 AM, said:

no go.. I tried both grounds with no luck.. I did test the rca by sticking the wires into the back of the plugs on my 3do to test the cable itself and it worked fine.. Is there any other options?

Most likely your bios is gone then if all your CAPS are good and your not getting any signal form any of the Video or Audio leads. I've had this happen to a Jaguar before and I just poped in a BJL eprom from morethangames and it worked after that.

[junkyardjedis]

Yeah it doesnt look like any are leaking and none are buldged so everything look clean. I did resolder the RF mod on the board as well as lightly sanding the grounds on the bottom due to slight oxidation.. Thanks I will contact more than games about the bios chip. I can use regular games with the BJL chip right? or do I need to buy the additional adapter?

Edited by junkyardjedis, Mon May 23, 2011 3:05 PM.

[Zerosquare]

You can play cartridges games just fine with the BJL chip, all you have to do is to press the B button on the pad to start the cart.

The Jaguar is a pretty complex system and there are literally dozens of things that could cause a black screen (defective ROM/RAM/68k/Tom/Jerry/clock, etc.). Without an oscilloscope and lots of time to spare it's pretty hard to spot the problem.

[junkyardjedis]

oh I see so maybe I would be better off just looking for another working unit?

[Zerosquare]

If you didn't spend too much on this one, I think it would make more sense, yeah.