Can someone tell me why my TANDY 1110HD computer will not power on?

[Duanea1965]

I just bought a used TANDY 1110HD portable computer on EBAY about 1 month ago. It did power on with the original AC power cord. The disk drive needs a belt. But I get a DISK BOOT ERROR. Press "F1" key. The screen turns on. Now the computer does not POWER ON what so ever.

Now the TANDY 1110HD will not power on. I checked the motherboard and I see no burned out parts. I dont know what to do.

The hard drive looks BRAND new and the arm moves freely over the disk plate. I dont know if I have to format the HARD DRIVE in order for it to work. I have the DOS disks and other software. I would like to get this TANDY 1110HD computer running.

Any support, help or advice is appreciated. Email me at DuaneA1965@Gmail.com

Thanks for your time.

Duane

 

[mojorific]

My only thought is that perhaps the battery has died. I know in my 1400 Tandy that I have to plug it in and wait until there is a charge in the battery before it will boot up successfully.

If the battery is completely faulty, I would assume that it would not boot at all.

 

[Juror22]

The 1110 HD does not require a battery to boot, if the ac adapter is plugged in. I have a working one and one that I bought one for parts some time back that did not boot, but I have not had time to sort out the issue on the broken one.

 

[Juror22]

For future readers of this thread who need to find out what happened, the issue is with the Fuse at F1.
I traced the issue with this machine and one of the 2.5A fuses blew. Jumping over it (temporarily to troubleshoot) got it posting again. While I wait for a replacement fuse, to make a permanent fix, I got curious and checked my other parts machine (had some corrosion damage) and the same fuse is blown. I jumped over it (briefly)and was able to get it to post as well, but it is still too sick to completely startup.

I need to find what F1 is protecting, but my guess is that either the HD (less likely) or the Floppy (more likely) is pulling too much current when they are non-functional.

Why no schematics for this model, Tandy, why?

 

[Dwight Elvey]

The list of things that can fail is way to large to
be worth printing. You have to analyze things, starting
from the power supply and in.
A fuse blown is a bad indicator.
Dwight

 

[IBM Portable PC]

.......... I need to find what F1 is protecting, but my guess is that either the HD (less likely) or the Floppy (more likely) is pulling too much current when they are non-functional.

Why no schematics for this model, Tandy, why?

1. Replace the fuse once more
2. Remove the HDD and HDC and FDD
3. Power up and see if it runs for several hours without the fuse blowing.
4. Power down and add FDD, run for several hours and boot from floppy several times.
5. If you get this far, it's the HDD/HDC which you may want to replace with a CF card or perhaps like me with a 3.5" Magneto Optical drive (512MB, 256 byte per sector disks).

Either the 1000 Service Manual, or the 1000A supplement should cover your machine.

 

[rlauzon]

Since I spent the better part of 20 minutes trying to figure out where the fuses are (since they don't look like fuses to me), here they are. They are the white, rectangular items.

 

[Juror22]

I'm glad you found them. Sorry that I didn't post pictures of them back in the day to save you that twenty minutes.

 

[rlauzon]

I'm glad you found them. Sorry that I didn't post pictures of them back in the day to save you that twenty minutes.

Oh, well, 20 minutes lost. 2 Tandy 1110HDs saved. I say that's a good trade.

I got out the multi-meter and checked F1. Sure enough, it's popped.

And the good news is I know why it popped on both units. So all I need to do is replace F1 on both.

 

[Juror22]

2 Tandy 1110HDs saved.

Always good to hear! Don't forget to replace the battery while you are in there (if you haven't already). I finally went back in late last year and replaced mine.

 

[acadiel]

Either the 1000 Service Manual, or the 1000A supplement should cover your machine.

I know this is an old quote, but no - the 1100 is a Panasonic/Matsushita made laptop, the 1000 is a desktop. Nobody has yet released the 1100 schematics (or allowed them to be scanned), and we are still awaiting for them to pop up. The 1100HD and 1100FD are the same machine except for the IDE connector (which I believe is attached to the short ISA bus that the BP-150 has, and the 1100-FD has the solder points for) for the EMS RAM card. The schematics should be close when we find the service manual for both.

 

[rlauzon]

The 1100HD and 1100FD are the same machine except for the IDE connector (which I believe is attached to the short ISA bus that the BP-150 has, and the 1100-FD has the solder points for) for the EMS RAM card. The schematics should be close when we find the service manual for both.

Having worked on both machines, I can say that the 1110HD and 1100FD are VERY different. Many of the components may be the same, but about the only things that can be swapped on them are the floppy drives and (probably) the LCD.

For example, the 1100FD has DOS in ROM where the 1110HD has no capability for that. There's nothing on the motherboard that would allow for another ROM.

 

[acadiel]

Having worked on both machines, I can say that the 1110HD and 1100FD are VERY different. Many of the components may be the same, but about the only things that can be swapped on them are the floppy drives and (probably) the LCD.

For example, the 1100FD has DOS in ROM where the 1110HD has no capability for that. There's nothing on the motherboard that would allow for another ROM.

I haven't seen the close up pics of the HD's motherboard - only the 1100FD and the BP150, so I was under the assumption they were just using the short ISA bus on the FD as an XTA (8 bit IDE) drive. It'd be great if someone could post comparison pictures. The 1110HD sounds like it didn't have a Panasonic counterpart, then, if it was drastically different. The 1100FD and BP150's motherboards are almost identical, save the 1100FD lacks the backlight daughterboard and the connector for the short ISA bus (and the ROM image is different for booting DOS, and doesn't have Deskmate). Edit: I did find some - here's a side by side - apparently, the backlight daughter board mount is still there in the 1110HD, too! (I wonder if one can be retrofitted there too, because one can definitely be retrofitted into an 1100FD.)