I have a Q-see Qt428 it belongs to my brother. he reported that after a power surge it would not start up properly.
unit is 12 years old. I did some checking and found that every single
capacitor on the board is bad. So I replaced them. same results won't
fully start up.
tried a different power supply. same results. replaced HD no dice.
after about 6 to 8 hours of searching the internet I stumbled on an ebay
review that states the devices can be recovered by putting firmware on a
USB stick and turning the unit on, the device would supposedly load the
firmware. Problem is I don't have any firmware.
contacted the reviewer and had to play 20 questions, he pointed me at a
supposed firmware file which when put on usb stick and placed in the
unit, got accessed but did nothing more. I contacted "q-see" and have
not yet heard back from them.
this device gave my googlefu a massive work out. I went on a wild goose
chase for firmware (which ended up NOT being the problem).
Every single electrolytic capacitor in this device was bad, very high
ESR to not even being seen by my capacitor testers. how it was working
at all I do not know.
Before
After
Replacing the capacitors did not change anything.
So in my searching I found little tidbits of information here, and there like:
this unit is the same as a TVT TD-2308SE which led me to TVT's site
where I found GARBAGE instructions on how to access the linux OS on the
unit through ye olde fashioned RS232 com port. the purpose of which was
to upload firmware which their site had none of.
Now of course all my new computers don't have a COM ports s
o
I had to dust off an old DELL laptop I keep for such instances. BUT the
unit has a TTL com port and cannot directly interface with RS232.
luckily I had a TTL to RS232 converter I got for another proje
ct
.
of course there are no pinouts on the main board of this unit as to what is what. but I determined where +5v and ground were.
said a hail Mary and plugged it in.
just friction fit and did not push it through all the way.
next I consulted the worthless TVT doc which had zero information on
the what settings to use. It ended up being 115200bps n,8,1, software
handshake.
as soon as I put that in to putty and connected I saw a prompt and
something constantly repeating about there being no more space. I spent a
good hour trying to follow the instructions to update the firmware with
the supposed firmware that the ebay reviewer directed me to. It never
worked.
after a crash course in linux commands (I'm a Windows and DOS guy) I
went to plan B trying to fix the file system since it appeared the flash
memory was full. I finally located a TMP folder and noticed a 490k file
with a name (similar to) zxzycxwv or something like that (probably a
random name). I deleted it, and the error message about no more space
disappeared. I restarted the device and BOOM it started up normal and
the only information lost was the time and date (dead CR2032) battery.