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[TjLaZer]

OK guys, I am having trouble getting a A500 Starboard 2 working! I get a flashing red LED on powerup and usually get a GURU. If I turn off and reseat the card, and power up I get no GURU but there is no RAM or stardrive.device present. It is fully loaded with 2MB too. I suspect I need a AC adaptor as it has a port for it on the back... Trouble is I do not know what volt adaptor to try!

[Metalguy66]

Hey TjLaZer... Nice to see you on the Amiga forums..

Hey listen.. Since we know the A1000 starboard doesnt need an extra PSU, and all that RAM is standard 5v parts, we're pretty sure that it needs a 5vdc supply..

The question is, are there any transformers, rectifiers, or regulators in there? If so, email me and we'll discuss how to determine an appropriate power input type/range... If not, then all you have to do is figure out where to put +5v and Ground.

First, you should look it over real good and see if theres any jumpers to allow it to draw power from the A500.

If no luck there, just get an ohm meter and check from the VCC pin of one of the chips to the power connector. Whichever pin of the power connector reads near zero ohms (like less than 10), is your +5v input. Whichever pin reads near zero to the ground plane of the board is ground..

Unless that thing has provisions for powering a drive inside of it, it shouldnt need any other supply voltages.

[JLF65]

The A500 model NEEDS the power. I used one for a time. Make sure you hook it up to the correct source or you'll fry your expensive and irreplaceable board. In fact, the A500 NEEDS more power than the stock supply can supply or things like accelerator cards won't work. When I was running my A500, I used a 125 W supply with it.

[Metalguy66]

Heh. I havent noticed that at all.. And unless that starboard is an EXTREMELY inefficient design, I find it hard to believe, unless (as I stated earlier) its actually spinning a hardisk inside the unit off the same power..

My A500+ has a 68030@50mhz, 68882@50mhz, 32 megs of ram, PLUS a GVP sidecar with 8 more megs of ram and a 3.5" desktop hardisk, all running off the stock A500 psu.. and no problems whatsoever..

My other A500+ has the same GVP sidecar, also with 8-megs of ram and a desktop hardisk, and it uses a single stock A500 PSU..

My Rev 6a A500 has a supra 500XP sidecar with 8 megs of ram and a desktop hardisk inside it, and (yep, you guessed it) runs off the stock A500 PSU..

Ive never had any problems running any of these machines this way.. In fact, Ive noticed that some PC power supplies cause a noticeably degregation of the audio clairity/quality on A500s..

Anywayse.. If theres no jumpers to enable "shared power" in that thing, then I'd reccomend going with a second PSU for it... That old DIP package DRAM is pretty power-hungry by comparisson to later chips used on SIMMs.. So its quite possible that it does need some serious "juice" to run it...

But the A500 PSU does have quite a bit of "extra capacity".... It has no problem running the A500, an accelerator, and most modern low-powered add-on devices..

[BuzzBrain]

My A500+ has a 68030@50mhz, 68882@50mhz, 32 megs of ram, PLUS a GVP sidecar with 8 more megs of ram and a 3.5" desktop hardisk, all running off the stock A500 psu.. and no problems whatsoever..

My other A500+ has the same GVP sidecar, also with 8-megs of ram and a desktop hardisk, and it uses a single stock A500 PSU..

My Rev 6a A500 has a supra 500XP sidecar with 8 megs of ram and a desktop hardisk inside it, and (yep, you guessed it) runs off the stock A500 PSU..

I asume you use the orginal external power for the GVP devices?
So, the SCSI/IDE disk and the 8mb memory use own power?

[bigmac]

:-D

TjLaZer wrote:
OK guys, I am having trouble getting a A500 Starboard 2 working! I get a flashing red LED on powerup and usually get a GURU. If I turn off and reseat the card, and power up I get no GURU but there is no RAM or stardrive.device present. It is fully loaded with 2MB too. I suspect I need a AC adaptor as it has a port for it on the back... Trouble is I do not know what volt adaptor to try!

Hi! all, quick question regarding this starboard, does it have the clock module? If it does then check to make sure you have a battery installed as its part of the main circuit it may not work without it hope this helps.
cheers :-D

[Metalguy66]

BuzzBrain wrote:

I asume you use the orginal external power for the GVP devices?
So, the SCSI/IDE disk and the 8mb memory use own power?

You assume wrong.. EVERYTHING on all 3 systems runs off of the A500 power supply. I dont use the GVP external power supplies at all.. In fact, I dont even know where they are.. Ive never used them. The stock A500 PSU runs everything just fine.. and for hours on end... and has for years..

[countzero]

Metalguy66 wrote:

Ive never had any problems running any of these machines this way.. In fact, Ive noticed that some PC power supplies cause a noticeably degregation of the audio clairity/quality on A500s..

I think it has to do with weak -12v on the PC PSUs compared to Amiga. Paula uses -12 AFAIK.

[darksun9210]

doesn't the GVP HD8 sidecar need to be modded to close 4 jumpers to allow it to draw power from the A500?

my A530 (40Mhz 030/882, 8mb ram, scsi2ide bridge, 4Gb CF card) has a molex socket soldered to the PSU input, and a molex plug off of the floppy drive power port of the A500, and all runs off the A500 PSU. i havn't checked my HD8 yet, but since its PSU bit the dust, i havn't used it. especially since getting an A530.

at the moment, that very same A500 PSU is running an A1200 with a blizz1240 (40Mhz 040),scsi module, 128MB ram, elbox IDE flyer, 4Gb CF card.

so A500 power is not a problem :-) just from the sounds of it, getting it into the starboard is whats needed.

(and yes, paula does need the -12v line otherwise you get horrible crackly audio... which doesn't seem to be what it should be on all PC PSUs - seen a solid -4v on the -12v line. looked like no problems for the PC it powered, but for an amiga, diffferent story.)

[Metalguy66]

doesn't the GVP HD8 sidecar need to be modded to close 4 jumpers to allow it to draw power from the A500?

You have to close 2 jumpers on the A500HD+ board yeah.. I really dont consider that a "mod" since GVP provided the on-board circuits to power the thing that way, and jumpers to enable the feature.. I think they knew the SCSI controller & DRAM would run "no problem", but included the external PSU as a "CYA" measure due to the fact that most hardrives at the time were still relative "power hogs" when compared with more modern drives..

so A500 power is not a problem just from the sounds of it, getting it into the starboard is whats needed.

Well, I have done some DRAM circuit design in my time.. And if the Starboard is making it's 2megs with old 256k x 1 DIP package DRAMs, it's gonna suck some juice..(It takes 64 chips to get 2 megs this way). Probably 750ma or better... If it's using 256k x 4 (only 16 chips), it's much less.

In the case of the GVP, the newer/smaller package DRAMs used on the vast majority of 30 pin SIMMs are much less "power hungry".. A 4meg SIMM that uses eight 1meg x 4 DRAMS only draws about 50ma...

(and yes, paula does need the -12v line otherwise you get horrible crackly audio... which doesn't seem to be what it should be on all PC PSUs - seen a solid -4v on the -12v line. looked like no problems for the PC it powered, but for an amiga, diffferent story.)

I bet you are exactly right about that.. I assumed it was just noise on the power circuits in general, but I did not bother to measure/scope any of the circuits. When I noticed the problem, I just got another stock A500 PSU which fixed the problem..

[TjLaZer]

ok I will have to crack her open and take a peek... It does have a fresh AAA installed, as the old one was starting to leak a little, hopefully it did no damage...

[JLF65]

Metalguy66 wrote:

You assume wrong.. EVERYTHING on all 3 systems runs off of the A500 power supply. I dont use the GVP external power supplies at all.. In fact, I dont even know where they are.. Ive never used them. The stock A500 PSU runs everything just fine.. and for hours on end... and has for years..

Somehow I don't believe you. Your "stock" A500 PSU is probably a custom one. I had/still have an A500 with the TRUE stock PSU, and it could BARELY power the 512K belly memory expansion and one external floppy. NOTHING else. Period. End of discussion. New and more powerful PSUs for the A500 did a brisk business in those days as the stock supply was good for nothing. Wherever you got your A500 from, the dealer almost certainly swapped your PSU for something more powerful.

The stock supply for the A1200 was even worse. Go to any Amiga magazine or any Amiga site and you'll see the same thing - those stock supplies couldn't power virtually anything at all. It's why things like the GVP had their own supply in the first place. They wouldn't have put it on there if it wasn't necessary.

[Damion]

There are a few different A500 PSU's. The stronger (35W?) is a champ, I used one to power an A1200/060 and a bunch of accessories for _years_ of daily use, no problem.

[motrucker]

TjLaZer wrote:
ok I will have to crack her open and take a peek... It does have a fresh AAA installed, as the old one was starting to leak a little, hopefully it did no damage...

This may only be part of the problem. Most of the modules need software to work correctly. The RAM expansion shouldn't though - that should auto-configure. BUT, is the FPU card in there? Without the software this may cause trouble.

[Metalguy66]

Somehow I don't believe you. Your "stock" A500 PSU is probably a custom one. I had/still have an A500 with the TRUE stock PSU, and it could BARELY power the 512K belly memory expansion and one external floppy. NOTHING else. Period. End of discussion. New and more powerful PSUs for the A500 did a brisk business in those days as the stock supply was good for nothing. Wherever you got your A500 from, the dealer almost certainly swapped your PSU for something more powerful.

The stock supply for the A1200 was even worse. Go to any Amiga magazine or any Amiga site and you'll see the same thing - those stock supplies couldn't power virtually anything at all. It's why things like the GVP had their own supply in the first place. They wouldn't have put it on there if it wasn't necessary.

I have 4 A500 PSUs.. They came from all different sources and I use them interchangably between systems with no problems whatsoever. They all bear the same part number (312503-01), but one is noticably heavier than the other three.. And interestingly, the heavier one is rated at less current (4.3a) on the 5v circuit than the other three which are rated at 4.5a... The 12v circuits on all 4 are rated at 1a, and the -12v circuits are all rated at 100ma(.1a).

All of my machines are rev 8a or rev 6a.. And all three run fine (and have for years) fully loaded with side-car, internal hardisk, and extra ram... and NO ADDITIONAL PSU..

If you have a hard time believeing this, than I dont know what to tell you other than "sucks to be you"... I sympathise with your past problems, and I suspect that you had earlier and more "power-hogging" designed hardware than is employed in the systems/add-ons that I have..

I guess I could hook my ammeter in-line with the 5v circuit on the PSU of each machine, to see exactly what they are drawing in terms of current, but I really havent the inclination to do so.. Like I said.. It's all worked great for years..