Almost there: Boots sometimes?

Hi,
I finished installing my chip, and noticed that the games boot sometimes, and othertimes would give me a black screen.

I have upgraded the firmware, but did not install boot manager. With boot manager installed, the games just don't work at all, it hangs at the "Please Wait" screen.

Do you guys have any tips?

I figure it might be a loose connection or a cold solder point, are there any easy ways to test whether a solder point is good or not?

Thanks a lot,
-Cuppo

[SOLUTION]
I got my ps2 working today. Awesome!
Here's a reference to other people that may have the same problem.
When upgrading the firmware from a CD, make sure that you burn the CD on good quality CD-R using Alcohol 120% on the slowest speed possible.
I re-installed bootmanager and reflashed the firmware from the good CD and all was well.

PS: Is there a special procedure to burn dual layer discs? I tried burning Street Fighter to a dual-layer disc but I only get black screens. It works perfectly fine if burned to a single-layer though.

I'm having a lot of trouble getting my chip to work completely...and it seems my symptoms are different than everyone elses.

Symptoms:
1) "Disc Check" on the firmware CD, says "PS1 Disc Authentication Failed. Please check SX Wire." - I opened up the playstation and resoldered it twice, with the same message appearing both times.

2) Using BootManager I can boot original ps2 games but I cannot boot any backup games. It hangs at the "Please Wait" screen.

3) Without using BootManager, I can boot up original games as well as a StreetFighter backup disc. All other backup discs hang at a black screen.

If someone can point me in the right direction and tell me where the problem might be, It'd help a lot.

Misc. Information:
The initial installation LED Test passes.
Firmware version cracked 34. BM v2.1.6
I'm burning games with DVD Decryptor at 2.4X speed onto a Memorex Dual Layer Disc

IIRC, normal single layer games will only run from single layer discs, you'd have to patch them to burn them onto a dual layer disc. It's the same for CD games, they don't work from DVD unless you patch them.

But I think the bigger problem is the crappy media you're using. Memorex blanks are really a waste of money, the worst DVD-R's I ever had. Only use Verbatim DVD-R discs, bad media is your lasers enemy no1.;)

best regards Jones23