[Robert A]

Thanks for the input. It must be the adapter. I cannot think of any other reason. I have 2 CH341a programmer boards, and the adapter doesn’t work in either of them, and I also tried without an extension cord on a tablet… Guess I’ll have to order another 1.8v board….

 

[Robert A]

So… I’m having a weird issue. Chip identifies in CH341a 1.29 WITHOUT the 1.8v adapter. Attaching the adapter, it cannot identify the chip. Same 1.8v adapter as everyone has pictured here, in the correct orientation…

 

Wondering if I should just give it a whirl and attempt to flash without the 1.8v adapter…

[Robert A]

So I did some testing.

Here are my findings:

• Being 10 feet from my router (Asus RT-AC66U), I had only about -71dB on average
• Take off metal backing with stock antenna, I get about -64dB on average
• Apply new antenna with existing antenna (I didn’t bother to desolder the old one, I just added on), with case off: -51dB
• Put back on metal backing with new setup, I get about -63dB on average

So the big limiting factor is that stupid aluminium back. I honestly can’t see a way to fix that from an internal standpoint. I’m not sure how iPads or other metallic backing tablets handle this, maybe a different antenna is necessary or it has to be very close and run along the edge of the case…

 

I have not tested with a wired ethernet adapter but I think wireless speeds on sites such as speedtest.net are being limited by the write speeds on the device itself… I can’t seem to edge out over 2mbps down, even with a wireless USB adapter.

[Robert A]

Blackburn wrote:

Buy a micro sma laptop antenna for mini pcie cards, cut the plug and solder that to the pcb wifi connector. You can find them on ebay and they have a much larger area for improved signal. Make sure you place the antenna near the top. on the metal rear housing is not a good idea, the metal alloy inhibits the signal and results will be poor. Or find a TP link micro USB wireless AC adaptor, open it up and remove the PCB and solder it to the inside of the USB 2 port.

 

That’s exactly what I ordered 🙂

[Robert A]

Bill Christiansen wrote:

From your pictures it looks like a bit of pressure on the coax cable where it runs over a component that looks like a diode. May just need a little repositioning. I would try that first as too much heat trying to unsolder will melt the plastic around the antenna conductors. My one I really can’t fault. It can see all the neighbors Wi-Fi and works fine in public hotspots.

 

I’ll see if I can’t gerry-rig it to the solder points without desoldering first, and see if there is an improvement in signal strength when the wire touches that point.

[Robert A]

Ivan wrote:

Wow….this antenna looks like crap. Post some results if you gonna solder new one. I have spare one from notebook, I dont know is there room for fit one but gonna post some updates if do. Thanks

 

I thought of using a spare one from an old laptop, but was unsure if it will be compatible with Wireless-N/Bluetooth also? I’m not an antenna expert but I think there is some slight difference for antennas for various functions. I ordered a pair off Amazon prime that is compatible. When it comes, I will try soldering a separate antenna on each point and test.

[Robert A]

The antenna really is a piece of crap. No wonder people have problems. See below for the patch (which I don’t know how much of a patch antenna that really is), and how it’s soldered onto the board. It looks like one wire is soldered in 2 places? Is that normal? Doesn’t seem like it to me. Looks like there should be 2 separate antenna pairs, one to each location.

 

[Robert A]

I will be attempting this sometime this week, not with that antenna but trying shielding first, and replacement second. Shouldn’t be difficult in my opinion and probably an easy fix. Wifi reception on this device is just ridiculously poor. I’ll update this thread when I’ve had the chance to look at it.

[Robert A]

I have bought a Matte screen protector from Aliexpress in the meantime. It seems slightly shorter (doesn’t cover the complete bezel) than the actual screen as if it was made for another tablet but the camera hole lines up, but I don’t see the edges of it underneath my fake leather case :p (also from aliexpress). Does work very well to prevent glare and hide distracting finger prints on the factory installed glossy screen protector.

[Robert A]

I have the pen, didn’t have to do anything to get it to work but the sensitivity is horrible. Unless it’s pressing right down straight, it won’t register a touch. So you can’t hold it naturally like a pen and write with the tip on an angle.

I wouldn’t recommend purchasing it.

[Robert A]

Well…I’ve bricked a Hi12 and ruined the BIOS chip. I bought another one (2 are still cheaper than a Surface Pro!). In the meantime, I wait for my heat gun and new winbond bios chip to replace, if that repair doesn’t work…I’ll attempt to dismantle the LCD and look at this to apply to my functional one.

What you’re suggesting does make sense…and seems like a no-brainer. It would help with brightness/glare and touch response also I believe.

If it’s not laminated with UV glue onto the LCD, how do you figure the glass is attached? Just with double sided tape around the edges? I can’t imagine that because if that would be the case on such a huge screen…you’d have dead touch spots in the middle and feel the flex with pressure…it must be some other method?

 

Edit: After reading some posts around the forums, I noticed that there quite a few people stating touch response is poor around the center, so perhaps it is just adhesive around the edges.

[Robert A]

I’m also in the same boat with a bricked Hi12

I ordered a programmer and a sop8 clip, I was too impatient for the 1.8v adapter to come and figured hearing of other people’s success, I thought I’d try without it.

So, everything went smoothly. It detected the chip just fine with the right model number everything. Flashed it with the battery wires desoldered. Flash verified to be the same as the bin file.

Touch the battery wires back (without soldering, and they measured 6.3v), try to power on, and nothing.

Retried with the older dual boot firmware, same thing. Bios chip reads and verifies great.

I can’t figure it out. Surely it wouldn’t verify correctly or even be subsequently readable if there was a problem after flashing.

 

Any ideas?

[Author]

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