Blank dead screen after upgrading the 497 handbox.

I have had the ETX 497 in storage for years and today connected the 497 with the 505 cable for for the purpose of upgrading the 43EG to the latest version.
The contacts were corroded and used a method to bring each key back to life.
The upgrade/downloading went just fine and the computer upgrade software, after a half of and hour, said "upgrade complete"
When I looked at the 497 handbox, the screen was illuminated, but just illuminated with nothing of assurance that the upgrade had occurred.
Disconnecting then and attempting to repower the handbox, nothing happened!
Now the screen is totally dark, no 12 volt supply will return the screen, and I can no longer connect to Meade for connections to the 497 handbox.
Without paying to send back to Meade, or buying another handbox, can anyone here refer me to the methods used to reset or return the handbox to its last state?
Thanks,
jim
Hope someone can help.
Jim

What version did you atempt to upgrade to?

Meade says 43Eg is the latest version.

I fear you may have bricked your HBX with an improper version. sorry though, I do not know how to get around this.

Theo

Thanks Theo.
I used AutoStar Upgrader and the software allowed communications and access to the handset.
It puzzles me why the upgrading would have taken place if the 43Eg was correct in the first place?
Jim

Strange, just found this Ebay listing a dead Autostar 497 where the fellow attempted to upgrade using AutoStar Upgrade and ran into the same difficulty.

http://www.ebay.com/...r-repair-/29...

Perhaps word to the wise, "if it aint broke dont fix it"
Jim

1. Make sure there isn't any corrosion in the serial port connector on the Autostar.
2. Verify your 505 cable is solid and reliable.
3. Download and install StarGPS, a free download.
4. Put Autostar in Safe Download mode.
5. Run StarGPS and let it do the firmware upgrade.

1. Make sure there isn't any corrosion in the serial port connector on the Autostar.
THE CIRCUIT BOARD IS ACCEPTING 12.38 VOLTS POWER CHECKED WITH A VOLTMETER ON THE CIRCUIT BOARD ITSELF.
2. Verify your 505 cable is solid and reliable.
THE 505 CABLE COMMUNICATES WITH THE 497 WITH CONNECTIONS TO THE LATEST AUTOSTAR WEBSITE, AND HNS SKY, CARTES DU CIEL, ETC..
3. Download and install StarGPS, a free download.
WILL DO THAT NOW.
4. Put Autostar in Safe Download mode.
BUT THE AUTOSTARS SCREEN IS BLACK BLANK BLACK..
5. Run StarGPS and let it do the firmware upgrade.

1. Make sure there isn't any corrosion in the serial port connector on the Autostar.
THE CIRCUIT BOARD IS ACCEPTING 12.38 VOLTS POWER CHECKED WITH A VOLTMETER ON THE CIRCUIT BOARD ITSELF.
2. Verify your 505 cable is solid and reliable.
THE 505 CABLE COMMUNICATES WITH THE 497 WITH CONNECTIONS TO THE LATEST AUTOSTAR WEBSITE, AND HNS SKY, CARTES DU CIEL, ETC..
3. Download and install StarGPS, a free download.
WILL DO THAT NOW.
4. Put Autostar in Safe Download mode.
BUT THE AUTOSTARS SCREEN IS BLACK BLANK BLACK..
5. Run StarGPS and let it do the firmware upgrade.

12 volts inside the Autostar says nothing about the serial port connection and connector.

A flaky 505 cable could work okay for telescope control but fail under the high-volume data transfer of a firmware update. A missing byte or two simply means you execute the telescope-control command again. Same thing happening in a firmware upgrade can mean failure.

An Autostar that only shows a blank screen on bootup might still respond to the Safe Download startup procedure.

If the above doesn't work, I may have a fix that has worked on a number of units I have repaired with same issues of a black screen. What may have happen is that a bad bit was written to the boot strap EEprom on the 68HC11. What this does is cause the HC11 not to be able to find the memory location of the Autostar program so it never loads. What you have to do is put the HC11 into "Boot Strap Mode"
To do this you need to open up the Autostar and carefully connect pin 2 and pins 3 on the 68HC11 to ground. You also need a downloader program for the 68HC11. I used one named "HCLOAD 6" and it works using the serial port, so you can use your RS232 cable. You turn on the Autostar and using HCLOAD you can down load what is in the EEPROM on the 68HC11. This is NOT the EEPROM were the AUTOSTAR program is located but a one located on 68HC11. One of the options in the HCLOAD program is to clear the internal EEPROM, writing zeros to all the memory locations, which I would do.
Then I would turn the unit off, but pin 2 and 3 back in there original state and turn back on the AUTOSTAR while holding the buttons which cause it to go into SAFE DOWNLOADER MODE. Reload the version of AUTOSTAR progam that you want and it should come back to life.

- Dave

Hi Everyone and thank you for your help.
Just to highlight some of the things I have verified:
No bad solder connections,
Key contacts cleaned prior to the trouble and HBox worked perfectly.
Voltage regulator is putting out 5 volts exactly.
Resoldered capacitors and cable pads to circuit board.
Tried the reset using Enter/Scroll Down and Power On all at once.
I am happy that DavidG is here with me on this one as I think he is on to something.
It's gonna take some time for me to sort through Davids method, but I know from the sunscope I built using his plans, he knows what he is doing and I hope to get some support from him as I load an EEprom, which I have never-ever done!
Thanks David and all...
Jim