I need to go back to an earlier firmware on my G70 in order to turn off the ABG and gain manual control of G2. If I can find some earlier EPROMs, is it OK to replace these alone or will I need to replace the Ya and Yb boards (which is where they sit, I gather)?
Is there a physical difference in the boards? Will I damage anything by simply transplanting the EPROMs? :confused:

Thanks!

I would take this for what it is...my vague recollection of sponging info from here...the firmware 'upgrade' is not able to be reverted. I'm not sure on the board swap. But i believe some people have been screwed if G2 levels had been altered prior to a tube swap/firmware upgrade.

i will leave confirmation and evidence of such to the other luminaries of the g70 club. :o

Thanks for the info newbieDAN but I’m not quite sure I follow you?

“the firmware 'upgrade' is not able to be reverted” – how come?

“But I believe some people have been screwed if G2 levels had been altered prior to a tube swap/firmware upgrade.” – What happened? Did the ABG not work under these conditions or what?

Bruce on G2 year 2004.....

In order to setup the G2 settings on a G70 according to the "factory" settings, it involves using an analyzer (and the Sony analyzer is preferable for these setting). The analyzer that Sony uses is attached to the lens face.

The Bias settings are set to the factory default levels and the G2 controls are used to adjust internal pluge pattern to gray at a level of 3 Nits. (1nit = .2923 ft/L)

The problem that seems to be occurring with the old firmware is that as the tubes wear, in order to obtain more output, people were raising the G2 setting instead of using the Bias to just keep the worn tubes balanced. Then, they upgrade the firmware, locking in those setting. When you finally replace the tubes with new ones, the G2 setting are now screwed up. The G2 settings should not be used to adjust for low end color balance on a G70, only the Bias controls should be touched.

Bruce on G2 year 2004.....

In order to setup the G2 settings on a G70 according to the "factory" settings, it involves using an analyzer (and the Sony analyzer is preferable for these setting). The analyzer that Sony uses is attached to the lens face.

The Bias settings are set to the factory default levels and the G2 controls are used to adjust internal pluge pattern to gray at a level of 3 Nits. (1nit = .2923 ft/L)

The problem that seems to be occurring with the old firmware is that as the tubes wear, in order to obtain more output, people were raising the G2 setting instead of using the Bias to just keep the worn tubes balanced. Then, they upgrade the firmware, locking in those setting. When you finally replace the tubes with new ones, the G2 setting are now screwed up. The G2 settings should not be used to adjust for low end color balance on a G70, only the Bias controls should be touched.

This does not say anything about the G2 not being reversable. It simply says that when installing new tubes the G2 will be out of wack. You should be able to reinstall the old firmware and adjust G2.

....locking in those settings....
:rolleyes:

http://www.avsforum.com/avs-vb/showthread.php?t=769188&highlight=abg

:rolleyes: Roll your eyes all you like but I think most people would understand that statement to apply to the later firmware. There does not seem to be any reason why one could'nt recall the original sony settings by reinstalling the original firmware. ;)

The point being (not mine by the way...an 'actual' G70 Guru..) is that G2 adjustment is rendered 'not adjustable' with the newer eproms. G2 is set at the factory using specialist equipment. If these settings have been altered at some point, for wearing tubes compensation, new replacement tubes AND firmware update will effectively lock in the old settings, and you can run out of adjustment 'range'

I've no idea how difficult it is to revert the firmware, but apparently it is possible.

I think the theory goes....leave the G2 at the factory preset, adjust bias and gain only.

I 'spose the million dollar question is what condition are the tubes in in Barcoed machine, and why does he want to disable the ABG?

G70 is 4500 chassis hours, original red, blue and green recently replaced with new, each <500 hrs.
All tubes 9.5 – 10 on Curt’s scale.
With ABG on, I run brightness and contrast at 65/65. The screen is a 1.25 white, 8ft screen. 4x3 (I have a lot of old TV shows in this format).

To explain the reason why I need the old firmware: The ABG line is brighter than a lighthouse, so when I get a fade to black which lasts longer than about a second (time for eyes to adjust) or a space scene with a black inky sky, or a very dark scene of any kind, I see the ABG lines – very irritating!
So I tried switching ABG off: Too dark. Even after adjusting the bias and gain and brightness and contrast it’s just too dark!

Thus I have three options:
1/ ‘Downgrade’ to the earlier bios, manually adjust G2, with bias and gain to default and brightness / contract in the middle range. Sit back, watch movies and smile.
2/ Sell the G70 and use something other than a Sony.
3/ Give up and remove the HT.

At the moment, this problem has got me so worked up and unless I can solve it soon, I’m heading for option 3, maybe option 2.

I have the same issue with mine but got no answers from anyone in regards to it. This thread explains a lot. I'm happy enough to leave the ABG on now, but what I would like to know is why don't I achieve proper shadow detail until I turn the ABG off, then on again. I have to do this every time I switch the unit on, or I never achieve any detail in darker scenes.

Well certainly don't consider option 3!

I have seen your photos in another thread and I see what you mean, and why you would want to disable the ABG...man that line is bright...be p*ssing me off too....I don't have any idea of why it's so bright...but I've three suggestions, one is a bit of a MacGyver-ing the others ...not so much.

I've heard (well...read) that some have gone to the trouble of placing some sort of tape on the C element, to mask that part of the tube face, probably much easier to do on a 16:9 config screen, I'd say fairly tedious to get perfect on a 4:3.

The other is to forget the 65/65 brightness/contrast with the ABG off and set them to MAX/MAX to see if your getting acceptable 'brightness', I'm not sure what possible (damage) effect this will have, long term on the machine, but I believe it doesn't drive the tubes any harder, more to do with what the tubes are emitting rather than the actual number.

The third, can you mask the screen with something like crushed velevet of some black hole type material that, at least minimises the intensity of the line?

Maybe someone can explain why your line appear brighter than most.....and if there is something that can be done about that.....

The tape method might be the quickest way to "sit back, watch movies and smile"

...oh, are the tubes OEM's or VDC's

All tubes are genuine SONYs not VDC.
Tape on the C element is not an option as the bowed lines extend into the active picture in all aspect ratios.
I believe the firmware ‘downgrade’ is the ONLY option apart from dumping the G70.

All tubes are genuine SONYs not VDC.
Tape on the C element is not an option as the bowed lines extend into the active picture in all aspect ratios.
I believe the firmware ‘downgrade’ is the ONLY option apart from dumping the G70.

Well it DOES seem like your only option is the firmware downgrade, ABG off, G2 dance.....

Try contacting Bruce or Terry...(Techman707 or Chuchuf) via PM, they will will be able to help you with your problem, and may even be able to get a hold of the eproms you'd need...and might be able to give you a work around, like shifting the active image area away from the AKB line...these are the Gurus you need to speak with.

I'll forgive you for blaspheming :)

I'm sorry to say that once you upgrade your firmware you cannot simply revert back to the old firmware by changing the firmware. There is a way o do it that requires getting into another chip and reprogramming it and Bruce knows how to do it. It's been years since I dealt with this problem and I will have to dig through my notes and see if I can find out what has to be done.

Terry

I really appreciate you taking the time to do this, Terry. As you can probably see from the post, the firmware ‘downgrade’ is the only way I’m going to be able to keep the G70.

Thanks! :)

Wouldn't it be easier to just to buy whatever boards you need from an older G70 to convert yours?

If I could find somebody with a suitable set...
That would sort one of the three G70s

I had the same problem with my G70 as well as a pulsing issue with ABG turned on. Fortunately I am using an HTPC so I have a lot of control over the Gamma. By boosting that and then having Ken Whitcomb calibrate the set I have been able to achieve a very nice picture with the newer firmware and ABG off. I am hoping moome's HDMI input card with Gamma will be enough to get a good picture from digital source components when I am ready to go that direction. I think there are a number of G70 owners using the latest moome HDMI input card, maybe one of them will chime in with an opinion on whether or not this works with no G2 and ABG off.