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Grid 286 1520 will not power on

oblivion

Veteran Member
Joined
Aug 28, 2010
Messages
975
Location
Scottsdale, AZ
I recently picked up a Grid 286 model 1520. when I plug it in (the 3 prong PSU) and hit the power switch the lower/external disk drive and battery charging/low lights blink and then nothing. Two of the many times I've tried to power it on it did start to boot and then shut off after a few seconds. I tried ejecting and reinserting the PSU but no luck. I've also left it plugged in for several hours but the same. I'm guessing the battery/PSU is dead but I have zero experience with this machine and laptops/portables in general. any advice on this thing? will I need to somehow replace the PSU (which I guess will not be easy or cheap)? also whats the standard power jack next to the 3 prong power plug? it looks like it takes a standard laptop charger.
 

Qbus

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Joined
Feb 23, 2011
Messages
913
Location
Salisbury Maryland
The DC power pod in the back of the computer provides 12 volts DC for the computer. By pushing the button under the pod it will pop out and you can put the battery in the same space.
Pop the power supply out by using the plug next to it you can connect an external 12 volt DC source. The case is grounded and one pin is the + but don’t remember what is what but that’s all that is required.
It may be less of a hassle to remove the pod and use clip leads to connect to the fingers inside the pod bay or you can test the power supply out of the computer but you have to be able to load it down to a couple amps load to properly test it.
Inside the computer is a DC to DC converter power supply that provides +12 and +5 to the system. Don’t know if its your issue but I have noticed a lot of failures of the capacitors in the power pod, may have something to do with them being so old?
 

shawnerz

Member
Joined
Mar 14, 2009
Messages
19
Location
North of Dallas, TX
Do you happen to have a DC power supply that can supply 16 volts at about 2.5 Amps? If so, you can eject the power supply (that's probably bad) and connect the external supply to the Grid. A common 12V DC supply will not work. You *might* be able to use a common 19 volt supply. But, you're pushing the upper limit of what the internal regulators will safely handle.
I did some testing a few years ago. I could get a 1520 to boot at about 14.5 volts. If it were booted at say, 16 volts, I could decrease the voltage to about 11 volts.
If you do have a suitable power supply, I'll post more info on what to do.
Thanks,
-Shawn
 

oblivion

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Joined
Aug 28, 2010
Messages
975
Location
Scottsdale, AZ
I don't have a 16v PSU unfortunately, been looking at thrifts and around the apartment but nothing, I may have to resort to ebay.
 

Qbus

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Joined
Feb 23, 2011
Messages
913
Location
Salisbury Maryland
Chalk one up for the Shawnerz, I just looked and they are indeed 16 volt pods. Could have sworn that I ran these on twelve or thirteen volts before! Anyway low voltage won’t do much harm being they were designed to also run from batteries.
Think that’s were the issue is that the DC to DC converter has a shutdown circuit to prevent damage to itself if the voltage drops below a set level but the problem is that when it first starts up it draws a lot of current and just know from experience that when the contacts are dirty the first inrush trips the protection and you get what you described in your initial post. The small amount of resistance across the contacts can cause a voltage drop that shuts the system down before it can start.
 

oblivion

Veteran Member
Joined
Aug 28, 2010
Messages
975
Location
Scottsdale, AZ
I acquired the power supply you suggested and set it to 16v. Unfortunately, I'm having the same issue. I hit the power switch and the light blinks briefly accompanied by a clicking sound and then nothing.
 
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